TW425794B - System and method for obtaining clock recovery from a received data signal - Google Patents

Abstract

A system for the evaluation of a timing vector to determine whether reliable timing recovery may be established at a predetermined center frequency, or from a specific pilot tone in the received signal. According to the present invention, the timing vector is created using band edge filters, a pilot tone timing recovery band pass filter, or other suitable means. The timing vector is then sampled a predetermined number of times. The sampled timing vectors are plotted on a complex plane to evaluate the general distribution of the sampled timing vectors. Timing recovery is then established using an acceptable timing vector as determined by comparing the distribution of the sampled vectors with a predetermined distribution threshold. In particular, a narrow distribution indicates minimum of signal noise, interference, or disruption, whereas a wide distribution indicates the opposite. The instant invention also includes a means of evaluating the timing vector at several center frequencies in the case of band edge timing recover until an acceptable timing vector is found.

Description

Yinben 425794 3621-pi f I doc / 002 A 7 _____B7___ of the Central Standards Bureau of the Ministry of Economic Affairs Ⅴ. Description of the Invention (丨) The present invention relates to the field of data communications, and in particular relates to the digital subscriber line (DSL) ) Time-reconstructed data communication. ’Data communication is getting faster and faster. The advent of DSL has made it possible for data communications in the public switched telephone network (PSTN) on existing copper wires between user modems and central office modems to be in the range of millions of bits per second. For conventional technology, the central room provides various users with access to the PSTN. In most cases, the user is connected to the central chamber via a pair of twisted copper wires. The central room provides a user interface to the PSTN. To facilitate DSL communication, a DSL modem is included in the connection in the central room to communicate with a DSL modem on the user side of the two-wire pair. DSL provides barrel-speed multimedia services hundreds of times faster than traditional telephone modems. DSL has several different architectures. One is ADSL, which provides data rates from 32 kbps to 8.192 Mbps, and it also provides telephone services. Similarly, RADSL is quite similar to ADSL, except that its bandwidth can be adjusted to suit the special application and the length and quality of the line. More specifically, the data speed of RASDL can be adjusted downwards to accommodate the distance from the central chamber. Other architectures include HDSL, SDSL, and VDSL.

Although DSL provides higher-speed data communications, it is not entirely problem-free. Especially at higher frequencies used in DSL communications, the traditional two-wire interface cannot provide a reliable data signal transmission path or channel. Usually, the interference signal is generated on the two-conductor channel from the second two-conductor channel whose channels are relatively close. This signal may be from the second DSL which is communicating with the same central office. 4 This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm)-(Please read the note on the back and fill out this page.) Order 4 2579 4 3621-pifldoc / 002 A7 B7 V. Description of the invention (the) The data machine is generated. Another issue is the quality of the two-wire channel itself. High-frequency communications often face large distortions in two-conductor channels. Similarly, the internal connection in the channel may decrease or loosen after a period of time, causing noise and further signal degradation. Therefore, data communication using DSL becomes more susceptible to interference that can cause data signal interruptions. As more DSLs are installed, the probability of interference between two conductor channels increases. Similarly, as the existing two-copper network becomes older, the quality of the channel deteriorates. In addition, the universalization of DSL and fast data communication speeds make users who are far away from the central office also want DSL services. However, longer distances will cause more serious signal distortions, because the quality will deteriorate, and the opportunities for interference and data signal interruptions will be greater. All issues will affect the quality of the DSL signal transmitted over the two conductor pairs. In particular, the information sent by the reconstruction of the data signal and signal determined by the special central frequency in the received data may be lost or reduced. However, it is now possible to transmit timing reconstruction information over a wide spectrum, where the timing reconstruction information may be reconstructed at any number along the center frequency of the spectrum. Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs (please read the precautions on the back before filling out this page) However, the signal deterioration, interference and interruption may endanger any number of received central frequencies along the transmission frequency spectrum Timing reconstruction information. In this example, the timing reconstruction cannot be established at such a central frequency, the receiver will need to randomly search for several possible central frequencies until the timing reconstruction is established. • This hit and error method will cause the inability of the data communication at the beginning. 5 This paper size is applicable to the Chinese National Standard (CMS) A4 specification (210X297 gong). Printed by the Bayong Consumer Cooperative, Central Bureau of Standards, Ministry of Economic Affairs, 3621-pifldoc / 002 A7-_B7_ 5. Description of the Invention (3) Delay of tolerance. Therefore, there is a need for a DSL receiver that can quickly evaluate the timing reconstruction information received at different central steps to determine whether the timing reconstruction + effective establishment. The present invention relates to a system and method for evaluating timing vectors to determine whether a timing reconstruction is effectively established. This system includes the creation and evaluation of timing vectors to determine interference and signal interruptions at a given central frequency. According to a preferred embodiment, logic is included to determine the center frequency of the timing vector to be evaluated. Spectral band edge filters are used to create timing vectors at special center frequencies. According to the second embodiment, the timing vector is established from a pilot tone. _Second, the timing vector is sampled by a timing vector estimator for a predetermined amount of time, thus resulting in several sampled timing vectors stored for analysis. The timing vector evaluator includes logic circuits that evaluate the distribution of the sampled timing vectors on the complex plane to determine the quality of the timing vector itself. In particular, narrow distributions represent low noise, interference, or data signal interruptions, and thus represent acceptable timing vectors. A wide distribution represents higher noise, interference, or data signal interruptions, and therefore represents an unacceptable timing vector. According to the present invention, a method for generating and evaluating timing vectors to determine the quality of data transmitted at a particular central frequency is disclosed. The method includes the steps of generating a timing vector, sampling the timing vector, and evaluating the quality of the timing vector by examining the sampled timing vector. Evaluating the frequency of the sampled timing vector further includes checking the distribution of the sampled timing vector on the complex plane. Second, the method includes determining whether the timing vector is acceptable based on the distribution of the sampled timing vectors. 6 Paper Sizes_CNS 橾 4 Specification < 210X297 Male jSlT " " (Please note on the back of S1 * before filling out this page): Packing · • Order J, 62l-pjf | cj 〇c / 〇〇2 A7 B7 V. Description of the invention (f) Brief description of the drawings: In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, the following exemplifies preferred embodiments and cooperates with all The drawings are described in detail as follows: Figure 1 is a block diagram depicting the main components of a conventional band edge timing reconstruction system of a conventional technology; Figure 2A is a spectrum showing a data signal without the need to expand the bandwidth; Figure 2B shows the use of Enlarge the frequency spectrum of the data signal for bandwidth transmission; Figure 3 is a block diagram depicting the main components of the spectrum band edge timing reconstruction system of the present invention; Figure 4 shows a diagram of the sampled timing vector taken from the high-quality timing vector; 5 shows a diagram of a sampled timing vector taken from a medium-quality time-series vector, FIG. 6 shows a diagram of a sampled timing vector taken from a low-quality time-series vector; FIG. 7A depicts the functional operation of the timing reconstruction system of FIG. 3 Process Figure 7B is a diagram showing the changes of the spectral band edge timing reconstruction system of Figure 3; Figure 8 is a flowchart depicting the functional operation of one of the blocks in the flowchart of Figure 7A: Figure 9 is a depiction of the present invention Graphical illustration of the timing vector distribution after sampling; Figure 10A shows the main components of the pilot timing reconstruction system of the present invention. 7 Central Consumers Bureau of the Ministry of Economic Affairs, Consumer Consumption Co-operative Printing 3621-pifldoc / 002 A 7 B7 V. Description of the invention ( $) Block diagram; Figure 10B is a block diagram of the main components of the dual-band and pilot timing reconstruction system of the present invention; Figure 11 is a diagram of the timing vector distribution of the pilot of the present invention after sampling; Figure 12 is based on Block diagram of the operating elements of the modem in the preferred embodiment; Figure 13 is a block diagram depicting a communication channel with a Nyquist filter; Figure 14 is a second block diagram depicting a communication channel with a Nyquist filter; Figure 15 Figure 12 depicts the operation of the in-phase and quadrature filters shown in Figure 12; Figure 16 is a diagram of the fundamental frequency rising cosine pulses used to calculate the coefficients of the in-phase and quadrature filters without bandwidth expansion; Figure 17 is used in calculations Illustration of the co-sine pulse of the fundamental frequency rising of the in-phase and quadrature filter coefficients of the bandwidth expansion; Figure 18 is a frequency diagram depicting the transmission spectrum without bandwidth expansion; Frequency diagram of the transmission spectrum with bandwidth expansion; Figure 20A is a frequency diagram showing the expanded bandwidth according to a preferred embodiment of increasing the bandwidth; Figure 20B is a diagram showing the expanded bandwidth of Figure 20A after being processed by the receiver The frequency diagram of the effect: Figure 20C shows the frequency diagram of the transmission spectrum received by the receiver with increased signal strength; s This paper size is applicable to the Chinese national standard (CNS > A4 specification (210X297 mm) (please ^ V Read the notes on the back of the page and fill in this page)-Order 362l-pifldoc / 002 A7 B7 V. Description of the invention (Dagger) Figure 21 is a frequency diagram of the transmission spectrum of the second embodiment of the present invention; Figure 22 is the present invention A frequency diagram of the transmission spectrum of the second embodiment; and FIG. 23 is a frequency diagram of the transmission spectrum of another embodiment of the present invention. Explanation of symbols: 55: A / D converter 57: first frequency band edge filter 59: second frequency band edge filter 61: recapture data 81: symbol 85: synthesizer 103: evaluator 104: memory 171 : Conduction frequency band pass filter 174: Timing frequency, printed by the Central Laboratories of the Ministry of Economic Affairs, Shellfish Consumer Cooperatives (please read the precautions on the back of the soil station, and then fill out this page) 179: BE / PT switch 209: Encoder 21 1: Precoding 213: In-phase filter 215: Quadrature filter 219: D / A converter 221: Filter 223: Channel. 225: Receiving data machine This paper size applies the Chinese National Standard (CMS) A4 specification (210X297 mm) ) 4257 9 4 A7 B7 3621-pifldoc / 002 V. Description of the invention (237: Noise 239: Equalizer. 243: Transmit square root shaping filter 245: Receive square root shaping filter 255: Totalize bus Dream test Figure 1 'Spectrum band edge timing reconstruction system 49 of its unfamiliar technology. Spectrum band edge timing reconstruction system 49 mainly includes a special application integrated circuit (ASIC) 51. ASIC 51 includes several different secondary Components, which may include several microprocessors Digital signal processors, known to the skilled person as "engine" and several digital logic circuits. In particular, ASIC51 is characterized by a data signal input 53 that is fed to an A / D converter 55. In the preferred embodiment, the A / D converter 55 oversamples the input data at three times the signal rate. This oversampled signal is tuned to a symbolic rate that will be described below. The industrial / consumer cooperative printed A / D converter 55 is in electrical communication with a spectral band edge (BE) device 56 which includes first and second EBs for recombining data obtained from the data signal Filters 57 and 59, and other digital circuits 61. For this application, the digital circuit 61 is not actually related to the operation of the timing reconstruction system of the present invention, which is well known to those skilled in the art and will not be described in detail here.

The first and second BE filters 57 and 59 are also labeled as "analytical" filters, and are characterized by responding to the complex responses to the digital signal input from the A / D converter 55, as known by those skilled in the art. Clear. The first and second BE 10 paper sizes are applicable to China National Standards (CNS) A4 specifications (210X297 mm) A7 B7 425794 3621-pif! Doc / 002 5. Description of the invention ($) Filters 57 and 59 are passed through the first A plurality of communication paths 65 are in electrical communication with the frequency multiplier 63. The first complex communication path 64 can communicate the real and imaginary parts of the complex responses of the first and second BE filters 57 and 59. The output of the frequency doubler 63 is a timing that is well known to those skilled in the art. The timing is in accordance with the bit rate of the data signal input 53. The frequency multiplier 63 is in electrical communication with the demodulator 67 via the second complex communication path 69. The demodulator 67 restores the oversampled data signal to a symbolic rate. In particular, each complex sampling is multiplied by the second frequency multiplier 71 with the relevant complex variable or vector e-f, so that the three complex sampling samples have the same phase angle. Note that in FIG. 1, the three complex variable numbers e'iwf are represented by rotary switches that are enhanced by each complex sampling received. The obtained complex variable numbers are averaged to obtain a single complex sample. The demodulator 67 performs electrical communication with the low-pass filter 75 through the electrical communication path 77. The communication path 77 communicates only the imaginary part of the complex timing vector samples obtained from the operation of the demodulator 67, which provides the necessary phase information by taking the inverse sine of the 15 parts of the imaginary part. The low-pass filter 75 @ reduces any unwanted noise in the signal. The phase information is communicated to PLLP79. This device is characterized by the digital logic symbol 81 and the cumulative equation F (Z) 83. Cumulative equation F (Z) 83 is in electrical communication with a synthesizer 85 located on DDL87 for its operation. Symbol 81 serves as a phase difference between the phase of the detection timing vector and the phase of the composite clock obtained by the synthesizer 85, thereby causing a phase error. This phase error is then stored in the cumulative equation F (Z) 83, which is then input to the synthesizer 85. The synthesizer M makes the 11 clock output of this synthesis paper size applicable to Chinese national standards (CNS > A4 specifications (2 丨 〇 X 2mm) > (Please read the precautions on the back and fill in this page) Ordered by the Central Standards Bureau of the Ministry of Economic Affairs, Consumer Cooperatives, Printing 3621-ρΐΓΙάοο / αα2 Λ / Β7 V. Description of the invention (q) Phase coincidence reduces phase error to 0. Therefore, the phase will be the same as the input phase The timing vector of the data signal 53. The synthesized clock is then used to trigger the A / D converter 55. Therefore, PLLP79 and DDL87 are used as phase-locked loops, which is a conventional technique. It should be noted that the above circuit can be completed by other architectures than ASIC. For example, the above device must exist on a separate integrated circuit located on a single circuit board. Similarly, the functions of PLLP79 and DDL87 can be completed by a VCO or other similar conventional circuits. Referring to FIG. 2A, the previous timing reconstruction is not discussed first. The frequency spectrum 89 of the data signal without bandwidth expansion is discussed. The frequency spectrum 89 shown has frequency bands 91 and 93 of the first and second BE filters (Figure 1). The frequency bands 91 and 93 are concentrated on the On the edge of the spectrum with a width of 1 / T, where T is equal to the symbolic period of the data signal. Note that the frequency passbands 91 and 93 are equally spaced from the center frequency fc of the spectrum. This center frequency fc is generally defined as equal to BE The frequency bands of the filters are 91 and 93. Reference is then made to Figure 2B, which shows the expanded data signal with a bandwidth 95 ("expanded bandwidth"). A general explanation of bandwidth expansion was disclosed in the application, 1997 US Patent No. 08/953083 of October 17, 2014, entitled "System and Method for Optimizing High-Speed Data Transmission", which is fully incorporated herein by reference. Similarly, the bandwidth is further explained Bottom. The first and second BE filters 57 and 59 pass bands 91 and 93 within the expanded bandwidth 95. The expanded bandwidth 95 allows the timing of the entire spectrum to be restored. That is, around the pass The center frequency fc with bands 91 and 93 may shift the entire expanded bandwidth 95 up and down as shown. Therefore, the frequency of this paper 12 applies to the Chinese National Standard (CNS) A4 specification (210X297 mm).

425794 3621-pif.doc / 002 5. Description of the invention (丨 pass bands 91 and 93 may be located anywhere between the extreme left 97 or the extreme right 99 of the expanded bandwidth 95 to obtain the hypothetical frequency pass bands 91 and 93. Timing recovery information from 1 / T. Repair trouble i # Refer to Figure 1 again. The problem of the conventional timing recovery system 49 is that it cannot be used at the multiple center frequency fC of the transmission data signal as shown in Figure 2a. Huan 4 obtains timing recovery. Similarly, it is not possible to determine the exact quality of K [timing vector at a given center frequency fc. This means that this system cannot determine the center frequency of the best fv. -Τ fan Y3 best timing vector, when When there are two or more acceptable center frequency leaves for generating data transmission. M Next, referring to FIG. 3, it shows the timing reconstruction system 100 of the present invention. Zhengqu According to the present invention, the BE device 56 includes a timing vector The evaluator 103 has a memory 104 that receives the complex timing vector output by the second frequency multiplier of the demodulator 67 through the third complex communication path 106. The timing vector evaluator 103 is the first and the first. Electrical performance of two BE filters 57 and 59 These components provide the characteristics of timing evaluation and control the selection of the center frequency according to the present invention. It should be noted that the timing vector estimator 103 may be located on other devices than the BE device 56. Before discussing the operation of the timing vector estimator 103 First, describe the characteristics of the timing vector seen by the timing recovery system before the phase lock occurs. The actual phase solution of the timing vector is random at the beginning of the communication. During transmission, general noise is introduced to the data signal and its cause The error of the phase solution of the time series vector itself. Therefore, if the time series vector is sampled multiple times and the sampled time series vector is drawn on a complex plane, the result is usually a vector "cloud". Generally, the displacement of a vector cloud or The size of the miscellaneous paper received by the distribution system and data during transmission is applicable to the Chinese National Standard (CNS) A4 (210 X 297 cm) (Please read the precautions on the back before filling this page) ^ ----- r --- Order --------- Consumption Cooperation among Employees of the Intellectual Property Bureau of the Ministry of Economic Affairs Du printed by the Central Standards Bureau of the Ministry of Economic Affairs Printed by the Shellfish Consumer Cooperative 425794 362l-pifldoc / 〇〇2 2. Description of the invention (丨 |) The signal is proportional to the amount of interference. Next, referring to FIG. 4, it shows a diagram of the first timing vector “cloud” 111. In particular, the first timing vector cloud 11 1 is a true slave The J-time points of multiple time-series vectors are marked. These multiple time-series vectors are obtained by sampling the time-series vectors output at the second frequency ^ 71 (β 3). Because the distribution of time-series vector diagrams is quite dense, The overall width of the vector cloud is also quite narrow, and the first timing vector cloud ill has local quality. The first timing vector cloud ill generally represents a reliable timing vector that can provide good timing reconstruction during transmission. Referring to Fig. 5, it shows the second time sequence vector cloud 113, which is of lower quality than the first time series vector cloud 111, but it is still acceptable in the time series reconstruction that this time series vector can achieve. The distribution of the second timing vector cloud U3 has an area much larger than that of the first timing vector cloud ul (FIG. 4), which represents that the sampled timing vector of FIG. 5 faces greater interference or distortion during transmission. The reliability of this timing vector is lower than the timing vector of the first timing vector cloud ill. Finally, referring to FIG. 6 ′, it is shown that the distribution of the second time series weight cloud 116 and the third time series vector cloud Π6 with a larger distribution area represent the characteristics of the time series vector that the time series restoration system 100 cannot establish. As shown, the sampling of the timing vector cloud of the third timing vector cloud is more random, which indicates that there is considerable interference and distortion when the data signal is received. As shown in Fig. 6, where the timing vector has such a bad quality, it needs to be converted to a different center frequency to see if a timing vector of better quality can be obtained. Referring next to Fig. 7A ', there is shown a flowchart 103 of the logic performed in the evaluation of the timing vector reconstructed using the band edge timing. In the box U9, the spectrum of the data signal is checked to determine the transmission bandwidth of the cutout 95;. Η This paper size applies the Chinese National Standard (CNS) Α4 specification (2 丨 0 × 297 mm) --- (please first (Read the note ^^ on the back and fill out this page)

A7 B7 425794 362! -Pif] doc / 〇〇2 5. Description of the invention (θ) degree. It is to be understood that block 119 need not be necessary, because according to the present invention, the transmitter may communicate to the receiver with a standard extended transmission bandwidth 95. In this example, the true bandwidth of the transmitted data signal can be set by the timing recovery system of the present invention. 'Second, in block 121, the center frequency is determined where the timing vector will be evaluated. Next, in block 123, the timing vector is evaluated at the selected center frequency. If the timing vector is unacceptable, the process returns to block 121 which determines the new center frequency and adjusts the band edge filter to operate at this new center frequency. If the timing vector is acceptable, the flow moves to block 125, where the timing recovery is established by starting phase lock. The action of block 121 to determine the center frequency of operation may change as the main goal of finding the center frequency of the highest quality timing vector in the least amount of time. In one method, several center frequencies can be identified at even intervals along the available range. · The analysis of the timing vector can start from the lowest center frequency and gradually proceed upward. The next selected center frequency is the previous evaluated center frequency plus the given amount, and it is performed to the highest center frequency of the frequency band until the order is found. Satisfied timing vector. In another method, the selection of the center frequency may start from the highest and lowest center frequency of the obtained bandwidth simultaneously. In this example, the center frequency may be added to the lowest value at the lowest point and subtracted from the highest point. Check that the center frequency at the timing vector can be changed between the highest and lowest points. The center frequency evaluation will be consistent at the center of the frequency band. If the center frequency of the only acceptable timing vector is at the highest point of the expanded bandwidth, this will have a faster timing recovery without the need to wait until the evaluation of the entire spectrum of this paper scale applies to the Chinese country, as in the previous method. Standard (CNS) Α4 specification (210X297 mm) (please ^: read the precautions on the back before filling this page)-°

I Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 425794 3621-pif 丨 doc / 002 V. Description of the Invention (θ) Yet another method is to randomly select the center frequency in the obtained bandwidth until an acceptable timing vector is found. In this example, it is better to store the center frequency of the time-series vector under inspection in memory to avoid repetition. The timing vector at a randomly selected center frequency is the lowest acceptable level. It is better to choose the next center frequency starting from the area in the bandwidth near the lowest acceptable center frequency, because in this area, there is no interference The probability of minimum distortion is greater. In yet another method, a plurality of center frequencies may be selected randomly or in other ways in a section spanning the expanded bandwidth, and each selected center frequency may be evaluated for the quality of the timing vector. Once the quality of several timing vectors is known, the center frequency that provides the maximum quality timing vector can be selected to perform timing reconstruction. Referring next to Fig. 7B, a completely different method uses a multiple BE filter pair I27 adjusted to many different center frequencies in a single time. In this example, ', the first and second BE filters 57 and 59 (Fig. 3) may be repeated, all connected to the same output of the D / A converter 55. In other words, it is not a single-pair including the first and second BE filters 57 and 59, but a bandpass filter using multiple pairs, each pair having an input terminal for receiving the signal of the D / A converter 55 . This type of band-pass filter pair must filter the same data in real time. Otherwise, the completion of the band-pass filter pair can be performed by the correlated multiples of 128 and 29, together with the timing vector estimator 103 which evaluates the timing vector of U7 for each band-pass filter. Finally, the quality of the timing vectors at several different center frequencies can be determined simultaneously. (6 C Please read the notes on the back before filling out this page) -111 Printed on a paper scale of the Central Bureau of Standards and Quarantine, Shellfish Consumer Cooperatives, China Standard Standard rate (CNS) A4 specification (210X297 mm) Printed by the Central Labor Bureau of the Ministry of Economic Affairs, Male Workers Consumer Cooperative 425794 3621-pin doc / 002 A7 B7 V. Description of invention (with) Quality is then input to determine which one is the most The best timing timing vector determiner 130. According to the decision result, the timing vector estimator Π0 will allow a pair of band-pass filters 127 to output timing information to PLLP79. The number of band-pass filters and other components used in this architecture can vary based on the number used on a single AS1C51. Similarly, the number of frequency multipliers 128 and or evaluators 103 may be less than the number of band-pass filters 127. In this example, the functions of the frequency doublers 128 and 129 or the evaluator 103 are distributed to two or more pairs of band-pass filters 127. The multiplier components used in Figure 7B will allow faster evaluation of timing vectors. For reliable data communications, there are many different ways to determine where the center frequency is to evaluate the timing vector. The main purpose is to find the most reliable timing vector in the least amount of time. Such methods are preferably included here. Referring next to FIG. 8, there is shown a flowchart 123 of the functional operation of the timing vector estimator for evaluating timing vectors according to the preferred embodiment. Starting from block 131, the time series vector is sampled a predetermined number of times, and the sample is stored in the memory 104. Sampling at neighboring points in time will result in neighboring vectors. Therefore, data can be sampled without loss of information. Next, in block 133, the reference vector is calculated from the vectors sampled in block 131. In the preferred embodiment, the reference vector is the average vector of the real and imaginary parts of the complex sampled vector divided by the sum of a given number of vectors. In the first variation, the reference vector is the longest vector faced. In a second variation, the reference vector may be the distance between the tail of the longest vector and the tail of the vector furthest from the longest vector in the preferred embodiment. It should be noted that the number of sampling vectors necessary to calculate the reference vector should be as small as possible in accordance with Section 17_ Standards of this paper (CNS) M specifications (210X297) ((Please read the notes on the back before filling (This page) -4_-Order A7 B7 425794 362] -pifldoc / 002 5. The invention description ([f) saves processing time, but it must be large enough to ensure that the calculated reference vector system is very accurate. In block 135, the maximum width of the sample vector distribution perpendicular to the reference vector is determined. This function is described with reference to FIG. 9, which shows the sampling_vector distribution 41 on the real and imaginary axes of the complex plane. 42 and 144. At the same time, several sampling vectors 143 and the average reference _ 144 away from the positive real axis at Θ angle are also displayed. ^ 4 ^ Note that the longest vector 153 can be used instead of the average vector 145. Similarly, because once the longest vector 153 is known, the farthest end I52 farthest from the tail end of I53 can be determined, so the axis I54 which can replace the above average vector appears. To find the width of the sampling vector distribution U1, the first and first sampling vectors 147 and 149 are determined. The first vertical sampling vector H7 is a vector having a maximum vertical distance D 1 from the reference vector axis 151 in a clockwise direction. Similarly, the second vertical sampling vector 149 is a vector having a maximum vertical distance D2 from the reference vector axis in a counterclockwise direction. The overall width W of the sampling vector distribution 14 is obtained by adding the two maximum distances D1 and D2. Note that the maximum distances D1 and D2 can be determined by calculating the vertical distance of each sampling vector and storing the calculated maximum number. _ Then return to Fig. 8. Once the width of the timing vector distribution is determined, execute block I37 to determine the overall width of the sampling vector distribution. Referring to FIG. 9, according to a preferred embodiment, the length L of the sampling vector distribution H1 is determined by the amount 値 of the longest sampling vector 5353, which is approximately 値. The length of the longest sampling vector 153 on the reference vector axis can also be determined. Returning again to Fig. 8, in block 139, it evaluates the distribution represented by the width W and the length L. According to the preferred embodiment, the ratio of W / L and the paper size of the paper are applicable to the Chinese storehouse standard (CNS) A4 specification (210 X 297 mm) (please read the precautions on the back before filling this page). Printed by the Central Government Bureau of Standards, Shellfish Consumer Cooperatives A7 B7 Printed by the Central Government Bureau of Standards, Shellfish Consumer Cooperatives 425794 362i-pifidoc / 002 V. Description of the invention ut) For the critical side of the acceptable time vector distribution Sampling time vector distribution [41] (Fig. 9) compared with a predetermined critical ratio. At lower ratios, it represents a narrow distribution with minimal noise. At higher ratios, it represents a wide distribution with large noise and interference. Therefore, in determining the critical ratio, those skilled in the art can understand that there is a low number to ensure that a reliable timing vector can be detected, and that the number is too low to find an acceptable timing vector with effective timing reconstruction. The proposed criticality may be between 0.8 and 1 and is a quality function of the phase-locked loop used. However, it is understood that the criticality is not limited by the recommendations of this preferred embodiment. For example, if the reference vector 154 (Figure 9) is used, it is possible that the acceptable ratio can be as high as two. The timing vector needs to be executed several times repeatedly to determine the exact ratio representing the acceptable timing vector. When a known amount of noise is introduced into the transmission channel, this can be achieved by determining the quality of the timing vector. It can be repeated several times until the critical ratio is found. Pilots Underneath, the above concepts related to the evaluation of timing vectors can be applied to pilots. Referring to Fig. 10A, a pilot timing reconstruction circuit 160 according to a second preferred embodiment of the present invention is shown. For band edge reconstruction, the input data stream 53 is fed to the D / A converter 55 again. This digital information is then fed to the conduction band pass filter 171 which produces a complex result. The conduction band pass concentration is thick. The complex output of the wave filter 171 is then input to the frequency multiplier 71. The timing frequency I74 is also input to the frequency multiplier 71. The resulting output of the frequency doubler is then fed to PLLP79 via LPF75. The output of PLLP79 is then fed to the D / A converter 55, which triggers the sampling function of the D / A converter 55 ° For the example with band edge reconstruction, the timing vector estimator 103 19 ___ This paper scale is applicable to China Standard (CNS) A4 specification (210X297 mm) {Please read the precautions on the back before filling this page)

4 25 7 9 4 3621-pifldoc / 002 A 7 B7 _ 5. The description of the invention (ΐη) is added to the pilot timing reconstruction circuit 160 to evaluate the complex number of the frequency multiplier 71. The quality of the timing vector output. The timing vector evaluator 103 may include a logic circuit that determines whether data transmission is to be continued based on the quality of the evaluated timing vector. 10B, a block diagram of a pilot timing reconstruction system 170 using band edge and pilot timing reconstruction is shown. In this embodiment, the timing reconstruction is established using band edges or pilots, depending on which is more reliable. In FIG. 10B, a band / pilot (BE / PT) device 177 includes a pilot band filter 171 and the first and second BE filters 57 and 59 described above. The complex output of the pilot band filter Π1 is fed to the BE / PT switch 179. The complex output of the band edge multiplier 63 is also fed to the BE / PT switch 179. The setting of the switch is calculated based on the timing vector by the timing vector estimator 103 at the band edge or pilot. If the on relationship is set to band edge reconstruction, the rotary switch 73 (Fig. 3) is activated and fed to the frequency multiplier 71. If the switching system is set to pilot reconstruction, the timing frequency 174 is enabled and fed to the frequency multiplier 71. A complex timing vector 106 obtained from a band edge or a pilot is fed to a timing vector estimator 103. The timing vector evaluator 103 may include a logic circuit that controls whether band edge or pilot timing reconstruction is used, or this logic circuit may be implemented elsewhere in this circuit. 'Next, referring to FIG. 11, there is shown a distribution of pilot timing quantities analyzed by the timing vector estimator 103. From the timing vector distribution obtained from the pilot timing reconstruction system, it can be found that the timing vector rotates along a fixed point at a distance from the origin. A good pilot timing vector cloud is formed in a generally dense circle along this point. Poor pilot timing vectors form less dense large circles. 20 The silver scale of this paper applies the Chinese National Standard (CNS) A4 specification (2I0X297 mm) (Please read the precautions on the back before writing this page) " Printed by the Consumers ’Cooperative of the Central Government Bureau of the Ministry of Economic Affairs n ^ 194 362l.pifi (j〇c / 〇〇2 A7 '' '~~~-, _____ __B7_ V. Description of the Invention (1¾) Therefore,' To evaluate the pilot timing vector, you only need to determine the general area of the distribution 'and take this The area is compared with an acceptable critical area. For further description, the distribution of the sampling vector 181 is shown. This distribution is generally circular. According to the logic of the time series vector estimator 103, first, the reference vector ° is determined at the first In the second embodiment, the reference vector 183 is obtained by averaging all the vectors 181. After determining the reference vector 183, the next step determines the longest vector 185 and the shortest vector 187 relative to the origin of the complex plane. The shortest vector The length of ι87 is subtracted from the length of the longest vector 185 to obtain the length L of the vector distribution. The width W of the distribution is determined by first finding the first direction of the longest vertical distance D1 on the complex plane above the reference vector 1S3. I89. Secondly, the determination of the width W of the second vector 191 ° of the longest vertical distance D2 below the reference vector M3 is determined by adding D1 and D2. The width w is multiplied by the length L to obtain an acceptable threshold. The area compared to the area ° timing vector is determined based on this. Acceptable or unacceptable. It is also possible to create a data signal with multiple pilots. In this example, the timing vector estimator 103 further includes a pilot frequency band filter Π1. Which logic circuit should be filtered to obtain the timing vector to be evaluated. The logic that determines the special timing vector can be framed to form any of several changes. For example, a special pilot can be selected randomly or sequentially, as in be In the example of filtering, 'selecting the center frequency is similar to the other methods discussed. Wide expansion In this point, the concept of the bandwidth expansion of a data transmission signal is discussed in detail' to better understand the present invention. Referring to FIG. 12, it is shown that the transmission has The size of the expanded frequency paper is applicable to the Chinese National Standard (CNS) A4 (210X297 cm) —Ί -------] installed -------- ordered ---- U (please read the back first Note Please fill in this page again.) Printed by the Central Bureau of Standards, Ministry of Economic Affairs, Consumer Cooperatives, 42,792,362l-pifldoc / 002 A7 _B7 V. Description of the invention (Η) The main practical and functional data transmission components of the wide data signal 201. The main actual components include ASIC203 and independent integrated circuit 205. ASIC203 includes several digital signal processors that operate according to special programs understood by those skilled in the art. Data input 207 is generated from a computer or other electronic device to be used Communication. Data input 207 is transmitted to the specified circuit on the ASIC 203 executing the encoder 209. The encoder 209 is a digital signal processor electrically coupled to the ASIC203. The AsiC203 is programmed with logic circuits to act as a precoder 211, an in-phase filter 213, an orthogonal filter 215 ', and an adder 217. ASIC203 is electrically coupled to the D / A converter 219 and the output filter 221 which are all on the independent IC205. The output of the adder 217 is input to 219 through this electrical coupling. The output of the filter 221 is transmitted via channel 223, which represents the communication path of the data communication to the receiving modem 225. To describe the general operation of the above system, the encoder 209 receives a data signal 207 output from a conventional computer or other device. The encoder 209 then generates a discontinuous in-phase signal 229 and a discontinuous quadrature signal 231. For those skilled in the art, this is CAP. The discontinuity of the in-phase and quadrature signals 229 and 2:31 is generated using modulation technology, in which several points on the data cluster are related to the special order of the bits of the input data signal, which is well known This technician understands. The number of different discontinuities that can be used for in-phase and quadrature signals 229 and 231 depends on the particular group used. Any of several different groups that can be used is from 8 to 2209 points in a 2 index. The operation of the encoder 209 will not be discussed in detail as it will be apparent to those skilled in the art. * 22 This paper size applies to China National Standards (CNS > A4 size (210X297mm) (Please read the precautions on the back before filling this page) 4 257: ..: '3621-pifldoc / 0〇2 A7 _B7___ V. Description of the invention (2 (?) The precoder 211 processes the in-phase and quadrature signals 229 and 231 to deform the transmitted signal in advance according to the channel characteristics obtained in the channel sequence. Generally speaking, when data is transmitted At this time, the receiver is serialized, and the receiving data machine 225 transmits the precoder filter coefficients to the transmitting data machine 20 + 1. The function of the precoder 2Π is well known to those skilled in the art, so it is not described in detail here. The conditions determined by the precoder 211 are that the in-phase signal will be processed by the in-phase transmission filter 213 and the quadrature signal 231 will be processed by the quadrature transmission filter 215. The in-phase and quadrature signals 213 and 215 are FIR digital filters The in-phase filter 213 and the quadrature filter 215 are also called "shaping" filters. This is because one of the purposes of the filters 213 and 215 is to discontinuous the in-phase and quadrature signals 229 and 231. Change to 'can be At the heart frequency, the waveform transmitted within the limited frequency bandwidth. In other words, the in-phase filter 213 and the quadrature filter 215 generate the resulting signal in the required frequency band. Printed by the cooperative (please fill in the notes on the back of the reading and then fill out this page). Then refer to Figure 13, which shows the flowchart of the filtering function related to the channel. The data signal 223 is transmitted by channel 223 by the Nyquist shaping transmission filter 235 Processed. The Nyquist shaping transmission filter 235 represents the functions performed by the in-phase filter 213 (Figure 12) and the quadrature filter 215 (Figure 12). When transmitting through channel 223, noise 237 is added to the data signal. 233. The equalizer 239 restores the signal transmitted through the channel by minimizing the signal distortion that may occur due to the pulse response of the channel 223. Similarly, the equalizer 239 avoids noise feedback to all The transmitted signal will minimize the noise 237 added to channel 223. Figure 13 Series 23 This paper size applies to the Chinese National Standard (CNS > A4 specification (210X297 cm)) Central Bureau of Standards, Ministry of Economic Affairs Printed by a consumer cooperative 425794 362 Bupifldoc / 002 A7 __B7_ V. Description of the Invention (II) An example of a transmission filter on the transmission side of channel 223. Referring to Figure Η, an example of a shaping filter showing distribution is not as j The function of the shaping filter is placed on the transmission of the channel as shown in Fig. 13. The structure of Fig. J 4 is characterized by the square root transmission shaping filter 243 and the square root receiving shaping filter 245 in the isochronous g 239. The function of the Nyquist shaping filter 235 (Fig. 13) can be expressed as the function of G (f) 'square root transmission shaping filter 243 and square root reception shaping filter 245 are Λ / ^ Τ). Considering Nyquist shaping, the series connection of the two square root shaping filters 243 and 245 provides the required Nyquist shaping filter, because the total pulse response of this series of filters is multiplied to obtain XV ^ Ti = G (f). Note that the square root shaping filter 245 is used in the logic performed by the equalizer 239, not a separate filter. In general, the use of such filters in the logic of an equalizer is well known to those skilled in the art. Reference figure 5 shows a digital filter 247 for one of the in-phase filter 213 or the quadrature filter 2 5. The symbol 249 is a discontinuous signal before the in-phase signal 22'9 (FIG. 12) or the quadrature signal 231 (FIG. 12) is input to the in-phase filter 213 or the quadrature filter 215. These symbols are separated in time by the representative period T. Since the symbol 249 is input to the filter 247, it is an upsampling process. Basically, the upsampling process involves injecting 0 samples between symbols to achieve a higher sampling rate. In the frequency domain, the upsampling process results in the duplication of the fundamental frequency signal every 1 / T. Above this, the sampling process is well known to those skilled in the art, so it is not described in detail. After the upsampling process, the resulting signal includes samples 253 separated by the sampling period X. For the sake of clarity, the symbol period T is related to the original 24 ^ paper size, using the Chinese national standard (CNS > A4 size (210X297) ^ (Please read the precautions on the back before filling out this page)-*- Order 425794 3621-pifldoc / 002 A7 B7 Printed by the Central Beech Consumer Bureau of the Ministry of Economic Affairs, Shellfish Consumer Cooperative, V. Invention Description (2) Time between symbols 249. After the sampling process, X is related to 253 samples That is, after the upsampling process, the symbol 249 is converted to the sample 253. In Fig. 15, the sample 253 is then fed to the digital filter 247. The digital filter 247 is a finite impulse response filter of this type. y (t) = C „x (t) + C 丨 x (tl) + C2x (t-2) +… + C„ x (tn) The coefficient Cn251 is multiplied by sample 253 and added to the total bus 255 Totalization. Sample 2S3 is separated in time by the sampling period X. After each totalization operation, sample 253 is shifted, and new sample 253 is input to digital filter 247. The output of the totalization operation is a discontinuous signal. 257. This special digital filter is described here as an example to provide a technical background. The configuration of the digital filter makes Only the coefficients are multiplied by the actual sampling data and summed up on the summation bus 255. This speeds up the processing time. This architecture is well known to the artist and is not described here. _ FIR filter coefficients 25 1 series It is found out by the decimated square root shaping filter G (f). In order to determine the coefficient 251 of the in-phase filter 213, the pulse response of the square root Nyquist fundamental frequency furnace wave generator is first defined. Generally, this response should follow Know the Nyquist limit. The pulse response g⑴ selected by the Nyquist fundamental frequency filter is the square root of the raised cosine placed in the transmitter and receiver, as shown in Figure 14, where the raised cosine function h⑴ is: {sinUr / Γ) ”cos_ / r)! πί / Τ / ll- (2« t / T)-The square root rising cosine pulse g⑴ is expressed as / tx Sin [^-(1-«) / '] + 4 ^ '〇〇5 [^ (1+ «) /']? K '[l- (4 at') 2] 25 This paper uses China National Standard (CNS) A4 (21 OX 297 mm)- (Please read the notes on the back before filling this page)

A7 B7-: ¾ / 3621-pif | doc / 002 5. Description of the Invention (θ) where t ′ = t / T, α is defined as excess bandwidth. It should be noted that the pulse response of not only the square root rising cosine can satisfy the present invention. Other pulse responses that can be used include the raised cosine itself and others known to those skilled in the art. Secondly, the center frequency fc of the spectrum of the CAP signal is determined. This is the maximum frequency at which the Fourier transform G (f) which is equal to or greater than g⑴ is non-zero. The pulse response of the in-phase filter 213 is defined as f (t). The pulse response of the quadrature filter 215 is defined as the Hilbert transfer function / 函数 of the pulse response of the in-phase filter 213. The Hilbert transfer function / ⑴ provides an impulse response orthogonal to the original impulse response f (t). This is necessary to add the outputs of the in-phase filter 213 and the quadrature filter 215 so that the data output from each filter can be pulled out at the receiver. The impulse response f (t) and its Hilbert transformation function / system are defined as f (t) = g⑴cos (2 7Γ fct), and / (t) = g⑴sin (2? R fct). Note that multiplying the function g (t) by the cosine function in f⑴ and the sine function in / ⑴ modulate the signal to the center frequency fc. Therefore, g⑴ can be regarded as a fundamental frequency signal. The coefficients of the in-phase and quadrature filters 213 and 215 (finite impulse response filters) are inserted by the discontinuity of time into the formula of the pulse response f (t) and its Hilbert transformation function / ⑴: Suppose A and The i-th coefficient 251 'of the in-phase and quadrature filters 213 and 215 are respectively composed of Ci = g (iT) [cos (2 7Γ fciT)] and di = g (iT) [sin (2; τ fciT)]. The number of different coefficients used in the in-phase and quadrature filters 213 and 215 may be as high as 180. It is possible to use more or fewer coefficients, depending on the desired frequency response. 26 This paper size applies to Chinese national standards (CNS > Α4 size (21 × 297 mm) (please read the notes on the back and fill in this page) -sf Μ Printed by the Central Laboratories of the Ministry of Economic Affairs Printed by the Shellfish Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs / 1 ^ ^ 5 ·; '., · A7 3621-pin doc / 002 I- B7 V. Description of the invention (4) • The same-phase and quadrature filters 213 and The coefficients within 2 15 are determined by finding the coefficients of the in-phase filter 213 and the quadrature filter 215 by first specifying the excess bandwidth α and the center frequency fc of the equation g (t) of the basic frequency band in which data transmission occurs. Next, t chooses to calculate the 周期 of the signal period Γ of the filter coefficients Ci and di. The selected signal period Γ is smaller than the true signal period T of the input signal. Although the conventional system is designed to minimize the bandwidth of the transmission signal Taking τ ′ as the signal period in equation g (t) will result in an increase in the transmission bandwidth. There are certain advantages from increasing the bandwidth, which are discussed below. For further explanation, refer to FIG. 16 , Which shows the graph of the fundamental frequency rising cosine pulse response h (t), where h⑴ The signal period used in the calculation is the true signal period of the in-phase signal 229 (Figure 15). Note that the curve passes the 0 axis at a multiple of the signal period t. Therefore, its curve meets the Nyquist condition. In particular, in the same phase Where the orthogonal signals 229 and 231 are shaped by this curve, the transmission bandwidth is the smallest. Now refer to FIG. 17, which shows an example of the fundamental frequency pulse response of the in-phase filter 213. Previously, the pulse response h⑴ It is set to be a raised cosine. However, T1 値 is used to replace the true signal period in the calculation of h (t), which is less than the true signal period T of the in-phase and quadrature signals 229 and 23. The result is an increase in transmission Bandwidth. _ Therefore, the coefficient d of the in-phase filter 213 (Figure 12) is ci = g (iT,) [cos (2? RfciT)], which corresponds to the discontinuity point along the pulse response curve [⑴]. Similarly, the coefficient di of the orthogonal filter 215 (Fig. 12) is di = g (iT _) [sin (2; r fciT,)]. Each coefficient is called a "tap (taP)". In 27_____ this paper Standards apply Chinese national standards (CNS > A4 specifications (210X297 mm) (Please read the precautions on the back first (Fill in this page) _ Order A7 B7 425794 3621-pifl doc / 002 V. Description of the invention (2Γ) There are up to 180 taps in the in-phase and quadrature filters 213 and 215, although more or less can be used. Ϋ́ Reference Figure 18 shows the nominal frequency bandwidth 259 obtained by using the true signal period T in calculating the impulse response f (t) in the spectrum. Figure 19 depicts the expanded bandwidth obtained by using T 'in calculating the impulse response f (t). In fact, replacing the true signal period T with T1 to calculate the coefficients of the in-phase and quadrature filters 213 and 215 (Figure 2) will expand the filtered signal in the spectrum centered on the selected center frequency fc. bandwidth. Therefore, the transmission extended bandwidth 261 is obtained by processing the fundamental frequency signal by a filter that calculates the coefficient with a signal period T1 that is less than the true signal period T of the unfiltered signal. Figure 15) The bandwidth of the signal processed by the filter to calculate the coefficients. Spreading bandwidth consists of signals with large interference between signals. T. The selected straight square is approximately 0.9T. However, it can be understood that T 'can be any number smaller than T, which is limited only by the amount of bandwidth expansion. The recognized fact is that it takes more energy to transmit _ than the expanded bandwidth. Similarly, the capacity of the receiving modem 225 will limit the allowable bandwidth expansion. Returning to Figs. 9A to 9C, an example of the expanded bandwidth 261 is shown, which is processed by the receiver 225 with dynamic equalization. In FIG. 20A, in the center region of the expanded bandwidth 261 that does not cause a frequency / broadband expansion, 1 / T width. Cross-hatched areas A and B represent the extent to which the bandwidth has been expanded. Once a signal with an expanded bandwidth 261 is received, the dynamic equalization in the receiving modem 225 will be sampled at multiples of the original signal rate. However, dynamic equalization basically produces one sample per signal. 28 This paper uses the Chinese national standard (CNS > A4 size (210X297 mm) (谙 Please read the notes on the back before filling in this page) Printed by the Central Standards Bureau, Shellfish Consumer Cooperative, 4257 S 4 3621-pifldoc / 002 A7 B7 V. Description of the invention (refer to FIG. 20B, showing the effect of the receiving modem 225 on the bandwidth. In the receiving modem 225, The received transmission signal undergoes a downsampling process, which causes the expansion ends A and B of the expansion bandwidth to move up or down by 1 / T. The expansion end A is shifted by 1 / T in frequency and expands End B is shifted down by 1 / T. Similarly, the entire expanded bandwidth is moved downward. Finally, the DC axis is centered, as shown in Figure 20C. The final result is shown in Figure 20C, where the expanded end A and B are located in the central area of the expanded bandwidth 261, and the expanded bandwidth 261 is then centered on the DC axis of the frequency spectrum. Therefore, the result obtained by the processing of the receiving modem 225 is that the baseband signal 252 is connected to the expanded end A and B — Rebuilding. Displace at the expansion end to its new position. In the process, the final result is that the picking ends A and B are added to the Ningxin area. Finally, the frequency amplitude of the central area will increase by 6dB, as shown in Figure 20C. Any noise system accompanying the expansion end is not added together. Because it is random in nature. Therefore, the whole signal to noise ratio of the original transmission signal 207 increases. The bandwidth is where the signal rate 1 / T is expanded once, and there is a gain of 6dB in the signal. For example, if Expanding the bandwidth 2.5 times, the baseband signal will have a gain of 12dB, and the remaining half will have a gain of 6dB. The increase of the signal-to-noise ratio of the original signal improves the interference and signal in the transmission using two conductor pairs The deterioration of the deterioration. ^ Therefore, the bandwidth expansion discussed here is suitable for the use of the conventional known dynamic receiving data machine 225. The receiving data machine 225 downsamples the transmission signal at a predetermined rate, and finally each signal generates a single Sample. However, the receiver's predetermined sampling rate is chosen to avoid the expansion of the expanded bandwidth 261 to itself. Returning to Figure 19, for further explanation, assume that the receiving modem 225 applies the Chinese national standard at 29 paper sizes. Standard (CNS > A4 specification (210X297 mm) (Please read the notes on the back before filling out this page) -i · A7 B7 Printed by the Central Standards Bureau of the Ministry of Economy Zhen 4 Consumer Cooperative 425794 3621-pifldoc / 002 V. Invention Explanation (21) 6 / T Bao / sec samples the transmission signal at the expanded bandwidth 261. In this example, the frequency band from 3 / T to 6 / T will be aliasing as known to the artist, "Fold over" to the frequency band from 0 to 3 / T. In the example of the extended bandwidth 261, the sampling rate of 6 / T at the receiving modem 225 is possible because the extended bandwidth 261 is not affected by influences. On the other hand, it is assumed that the reception modem 225 samples the transmission signal at 4 / T baud / sec. In this example, the frequency band from 2 / T to 4 / T will be folded to the frequency band from 0 to 2 / T. In this case, part of the expanded bandwidth 261 will be folded to itself. This is not allowed. This means that both the center frequency fc and the amount of bandwidth expansion should be normalized so that the expansion. The bandwidth is not in a position that is a multiple of one and a half times the sampling frequency of the receiving modem 225. This means that in the case where the transmission signal is sampled at 6 / T baud / second, the expansion bandwidth can be placed between 0 to 3 / T, 3 / T to 6 / T '6 / T to 9 / T' 9 / Anywhere from T to I2 / T ... Referring to FIG. 21, which shows a second method for expanding the bandwidth by establishing a first filter 2M and a second filter 283. Each of the first filter 281 and the second filter 283 has a nominal bandwidth. width) 259. The coefficients of these two filters are calculated so that the center frequency & is separated by exactly i. Signal rate 1 / T. In this way, the raised cosine of the transmission filters 2S1 and 283 can be used instead of the square root of the raised cosine to complete the flat in-band response. In fact, any other pass filter that complies with Nyquist criteria can be used. In general, the Nyquist criterion is quite familiar to those skilled in the art, so it is not described in detail here. Nyquist-compliant pass filters will have rolloff regions that provide a flat response when added. Referring to FIG. 22, another method that can achieve bandwidth expansion is shown. In particular, 30 paper sizes are applicable to Chinese i | Home Sample Standard (CNS) A4 specifications (210x29Fmm > * (Please read the precautions on the back before filling in this page)

Work and Consumer Cooperation of the Central Standards Bureau of the Ministry of Economic Affairs Du Yinzhuang 4 2579 4 WU-pindoc / OO] A7 B7 V. Description of the invention (stain) The first filter 285 and the second filter 287 with different bandwidths can be added. The difference between frequencies is equal to half the sum of the bandwidth. If the excess bandwidth of each of the filters 285 and 287 is adjusted to have the same rolloff rate, coefficients can be added as in the second embodiment to obtain an expanded bandwidth. For example, if the bandwidth of the first filter 285 is half the bandwidth of the second filter, the first filter will need two excess bandwidth to achieve a flat response. Note that in the second and third methods, the coefficients of the in-phase and quadrature filters calculated by combining two independent filters are equal to those obtained in the preferred embodiment. · In the fourth method, the transmission filter of the second or third method can be established, except that the two in-band regions do not need to touch. This method is useful if there is interference between the two good intervals of the received signal. Referring to FIG. 23, considering the second, third, and fourth methods, there is no reason why one or most of the added filters should adjust their intensity as shown, thus allowing a variable intensity transmission spectrum. Similarly, it is not limited to only two frequency bands. The resulting transmission filter may include addition of coefficients obtained from several different frequency bands. The methods described above show possible ways to extend the bandwidth of some, but not all, transmission spectrums. It should be noted that the bandwidth expansion using quadrature amplitude modulation is disclosed in detail here. It is to be understood that other methods include bandwidth expansion using pulse amplitude modulation. In particular, the characteristic of pulse amplitude modulation is that a single digital filter processes the in-phase signals independently. Therefore, the concept of bandwidth expansion discussed here is generally applied to the processing of a single in-phase signal, except that the pulse amplitude modulated signal is not modulated to the carrier frequency, but is centered on DC in the frequency spectrum. The special paper size is applicable to China National Standard (CNS) A4 specification (210X297 mm) (Please read the precautions on the back before filling this page) Order 362l-pifldoc / 002 A7 B7 V. Invention Description Pi) Otherwise, you can Calculate the coefficient of the filter whose signal period is less than the true signal period of the data signal with PAM. In summary, although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Retouching, so the scope of protection of the present invention shall be determined by the scope of the attached patent application. · (Please read the notes on the back before filling this page) Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 32 This paper size is applicable to the Chinese national standard (CNS > A4 size (210X297 mm)

Claims (1)

A8-B8C8D8 362l-pifldoc / 002 6. Scope of patent application 1. A system for reconstructing the clock in a data communication device, the system includes: 'a first processing device for generating a time series according to a series of data . A second processing device establishes a timing vector distribution according to the timing vector; and a third processing device determines the quality of the timing vector according to a graphical measurement of the timing vector distribution. 1 2. The system according to item 1 of the scope of patent application, wherein the first processing device further comprises a band edge timing vector generator. 3. The system according to item 1 of the patent application scope, wherein the first processing device further comprises a pilot timing vector generator. 4. The system according to item 1 of the scope of patent application, wherein the second processing device further comprises: a code that samples the timing vector a predetermined number of times; and stores one billion of the timing vector samples. 5. The system according to item 1 of the scope of patent application, wherein the third processing device further includes a memory; and a code stored on the memory to calculate an area of the distribution and the distribution of the distribution. The area is compared to an established acceptable critical area. 6. —A system for reconstructing the clock in a data communication device, the system includes: a device that generates a time series vector based on a series of data; 33 This paper standard applies to the national standard (CNS) A4 (210 X 297) (Mm)-^ ---------- ^ -------- Order --------- line. ^ ≪ 'Please read the notes on the back before filling (This page) Printed by the Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, A8B8C8D8 425794 3621 -pifldoc / 002 VI. Patent application scope 'A device that builds a time series vector distribution based on the time series vector; and measures based on the icon of the time series vector distribution A device that determines the quality of the timing vector. 7. The system according to item 6 of the scope of patent application, wherein the device for generating a timing vector based on a series of data further includes a band edge timing vector generator. The system according to item 6 of the patent application, wherein the device for generating a timing vector based on a series of data further includes a pilot sequence vector generator- 9. The system according to item 6 of the patent application, The device for establishing a timing vector distribution according to the timing vector further includes: a device for sampling the timing vector a predetermined number of times; and a device for storing the timing vector sample in a memory. _ 10. The system described in item 6 of the scope of patent application, wherein the device that determines the quality of the time series vector according to the graphical measurement of the time series vector distribution further includes: a device that determines the length of the distribution; a device that determines the length of the distribution; A device of width; a device of calculating the area of the distribution; a device of comparing the area of the distribution with a predetermined acceptable critical area. 11. A system for reconstructing a clock in a data communication device, the system includes: generating a time series vector from a received data signal at a predetermined center frequency 34 This paper standard is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) --- τ --------- ^ -------- Order --------- line.-T (Please read the note on the back B3 ' (Fill in this page again.) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. Printed by the Consumers Cooperative of the Intellectual Property Bureau of the Ministry of Economy. A device for sampling the timing vector; and a device for measuring the quality of the timing vector by evaluating the timing vector sampled at the center frequency. 12. The system described in item li of the patent application range further includes a device for determining the center frequency and generating the timing vector from the received data signal. 13. The system according to item 11 of the scope of patent application, wherein the device for generating a timing vector further comprises: an A / D converter having an input terminal and an output terminal; the input terminal is coupled to the A / D output terminal One pair of band edge filters, each band edge filter having an output terminal; and a frequency doubler coupled to each band edge filter, the frequency doubler having an output terminal capable of transmitting a timing frequency. 14. The system according to item 11 of the scope of patent application, wherein the device for measuring the quality of the sampling timing vector at the center frequency further comprises: a device for measuring the distribution of the sampling vector on the complex plane; and according to the measured distribution The device for determining the acceptability of the timing vector 1 5. The system as described in item 12 of the scope of patent application, wherein the device for determining the center frequency and generating the timing vector from the received data signal further includes a set of predetermined frequencies値 The device that determines the center frequency. 16. The system as described in item 12 of the scope of patent application, wherein the device that determines the center frequency and generates the timing vector from the received data signal is more suitable for this paper standard (CNS) A4 specification (210 X 297) (Mm)% Read the back item and fill in this page 〒 Page I w III Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs' 2 δ / Jaw 3621-pifldoc / 002 C8 Uo 6. The scope of patent application includes: Means for the spectral width of the data signal; and means for calculating a predetermined number of heart frequencies within the frequency spectrum of the received data signal. Π. The system described in item 14 of the scope of the patent application, Huai, wherein the device for measuring the distribution of the sampling vector further includes: determining an angle representing an angle of a complex sampling timing vector within a sampling timing vector distribution on a complex plane A device for a reference vector; and a device for determining the width and length of the distribution of the sampling vector, the width being perpendicular to the reference vector, and the length being parallel to the reference vector. 18. The system according to item 17 of the scope of patent application, wherein the device for determining an angle representing a reference vector of the angle of the complex sampling timing vector within a sampling timing vector distribution on the complex plane further comprises determining a reference vector from the complex sampling vector. Mean of Mean Vector. 19. The system described in claim 17 of the scope of patent application, wherein the means for determining the length of the sampling vector distribution parallel to the reference vector further includes means for determining the length of the longest vector from the complex sampling timing vector. 20. The cover rattan described in item 17 of the scope of patent application, wherein the means for determining the width of the sampling vector distribution further includes a means for determining the vertical distance of each sampling vector to the axis of the reference vector. 21. —A system for reconstructing a clock in a data communication device, the system includes: generating a timing vector from a predetermined pilot in a received data signal, 36 paper standards are applicable to the Chinese National Standard (CNS) A4 specification ( 210 X 297 mm) —; ------------------ Order --------- line--y (please 'first read the notes on the back) (Fill in this page again.) Printed by the Intellectual Property of the Ministry of Economic Affairs and Employee Cooperatives. Η as Β8 3621-pit'ldoc / 002 C8 _ VI. Applicable patent scope: The device for sampling the time series vector; and by sampling the center frequency A device that evaluates a timing vector to measure the quality of the timing vector. .21 As described in item 21 of the scope of the patent application, it further includes a device for determining the pilot, and using the pilot to generate the timing vector from a plurality of pilots in the received data signal. 23. The system according to item 22 of the scope of patent application, wherein the device for measuring the quality of the timing vector sampled at the center frequency further comprises: a device for measuring the distribution of the sampling vector on the complex plane; and the measured A device that compares its distribution with a predetermined acceptable distribution to determine the acceptance of the time series vector. '24. —A method for obtaining clock structure, including the following steps: generating a timing vector from a received data signal; sampling the timing vector; and measuring the timing vector by sampling at the center frequency to measure The quality of the timing vector. 25. The method as described in item 24 of the scope of patent application, wherein the step of generating a sequence vector further includes a step of filtering the received data signal with a pilot band pass filter. 26. The method as described in item 24 of the scope of patent application, further comprising the step of determining a center frequency to generate from the received data signal: the timing vector. I 27. As described in item 24 of the scope of the patent application, the quality of the time series vector sampled at the center frequency is measured by the following steps: 1J Step: 37 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) --------------- ^ -------- Order --------- line. Y Γ Please read the notes on the back before reading (Fill in this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 362'1-pifldoc / 〇〇2 C8 _ D8 VI. The scope of the patent application measures the distribution of the sampling vector on the complex plane; and it is determined based on the measurement distribution The degree of acceptability of the timing vector. 28. The method described in item μ of the patent application scope further includes the step of determining the pilot. Thus, the timing vector is a complex timing frequency from the received data signal. .29 · As Fang Yi __, which is described in item 20 of the scope of patent application, the step of generating a time series vector further includes the following steps: _ Converting an analog data into a digital output; use the digital output with a Filtering a band edge filter; and by filtering the band edge The output frequency of the filter is multiplied to generate a time series vector. 30 As described in the 26th aspect of the scope of the patent application, the method of determining the center frequency to generate the time series vector from the received data signal further includes: The frequency 値 determines the frequency of the center frequency. 31. The method as described in item 26 of the patent application range, wherein the step of determining the center frequency to generate the timing vector from the received data signal further includes determining the received data signal The width of the frequency spectrum; and 50. A predetermined number of center frequencies within the frequency spectrum of the received data fS number. 32. The method as described in item 27 of the scope of patent application, wherein the step of measuring the distribution of the sampling vector It also includes: the reference angle represents a reference vector of the angle of the complex sampling timing vector in one of the sampling timing vector distributions on the complex plane; and 38 this paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 11 < ------ --- ^! | Order ----- — — — —line ^-* {Please read the notes on the back before filling this page> 88 8 φ ABCD 425 794 3621-pifldoc / 002 6. The scope of patent application determines the width and length of the sampling vector distribution, the width is perpendicular to the reference vector, and the length is parallel to the reference vector. The method described above, wherein the step of determining an angle representing a reference vector of an angle of a complex sampling timing vector in a sampling timing vector distribution on a complex plane further includes a step of determining an average vector from the complex sampling vector. 34. The method as described in item 32 of the scope of patent application, wherein the step of determining the angle represents a reference vector of the angle of the complex sampling timing vector within a sampling timing vector distribution on the complex plane further comprises determining from the complex sampling timing vector The length of the longest vector. 35. The method as described in item 32 of the scope of patent application, wherein the step of determining the width of the sampling vector distribution further includes the step of determining the vertical distance of each sampling vector to the axis of the reference vector. (Please read the precautions on the back before filling out this page) W Pack -------- Order --------- Printed by the Employee Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 39 This paper is applicable to China National Standard (CNS) A4 specification (210 X 297 mm)